CN219496530U - Capacitance detection device - Google Patents

Abstract

The embodiment of the application provides a capacitance detection device, which comprises: the charging circuit comprises a charging power supply which is connected with the tested capacitor and charges the tested capacitor; a discharge loop which is connected with the tested capacitor and discharges the tested capacitor; a first detection circuit connected to the charging circuit and detecting a charging signal; and the second detection circuit is connected with the discharge loop and detects a discharge signal. Through the embodiment of the application, the diversity of the sampling data is increased, the accuracy and the stability of the capacitance detection result are improved, and the environmental adaptability of the detection system is improved.

Description

Capacitance detection device

Technical Field

The present disclosure relates to capacitive-based detection techniques, and more particularly to a capacitive detection device.

Background

In a capacitance-based detection system, detecting a change in the surrounding environment by a change in the external capacitance, such as whether or not there is a subject or a distance between subjects, is also an important aspect in such a detection system for detecting the magnitude of the external capacitance.

Currently, there is a technology for detecting the size of an external capacitor by means of charging and discharging, in the prior art, the external capacitor is often charged by an excitation voltage, and after the external capacitor is fully charged, the external capacitor is discharged, and in the discharging process, the voltage of a discharging circuit is detected, so that the size of the external capacitor is detected.

The inventor finds that in the existing capacitance detection technology, only the voltage of the capacitor in the discharging process is detected, the detection value is single, the detection result has the problem of instability, and the complex and changeable environment is difficult to adapt.

It should be noted that the foregoing description of the background art is only for the purpose of facilitating a clear and complete description of the technical solutions of the present application and for the convenience of understanding by those skilled in the art. The above-described solutions are not considered to be known to the person skilled in the art simply because they are set forth in the background section of the present application.

Disclosure of Invention

In order to solve at least one of the above problems or other similar problems, the embodiments of the present application provide a capacitance detection device, which detects corresponding charging signals and discharging signals in the charging and discharging processes of an external capacitor, respectively, so as to improve the reliability of the detection result and improve the environmental adaptability of the detection system.

According to an embodiment of the first aspect of the present application, there is provided a capacitance detection device, wherein the capacitance detection device includes:

the charging circuit comprises a charging power supply, and the charging power supply is connected with the tested capacitor and charges the tested capacitor;

a discharge loop which is connected with the tested capacitor and discharges the tested capacitor;

a first detection circuit connected to the charging circuit and detecting a charging signal;

and the second detection circuit is connected with the discharge loop and detects a discharge signal.

In one or more of the embodiments described herein,

the first detection circuit detects a current signal.

In one or more of the embodiments described herein,

the first detection circuit includes a first resistor connected in series with a charging power supply and a current detection circuit that detects a current flowing through the first resistor.

In one or more of the embodiments described herein,

the current detection circuit comprises a first capacitor connected in parallel with the first resistor and a first amplifier for amplifying voltage signals at two ends of the first capacitor.

In one or more of the embodiments described herein,

the first detection circuit detects a voltage signal.

In one or more of the embodiments described herein,

the first detection circuit is a voltage follower and detects a charging voltage formed by the tested capacitor in a charging process.

In one or more of the embodiments described herein,

the measured capacitance is a variable capacitance.

In one or more of the embodiments described herein,

and a controller that receives the charge signal detected by the first detection circuit and the discharge signal detected by the second detection circuit, and performs AD sampling on the charge signal and the discharge signal.

In one or more of the embodiments described herein,

the charging circuit includes a first switch that switches charging and non-charging states of the charging circuit;

the discharge loop comprises a second switch which switches the discharge and non-discharge states of the discharge loop;

the controller includes a timing control unit that outputs a timing control signal, and the first switch and the second switch perform a switching operation according to the timing control signal.

In one or more of the embodiments described herein,

the second detection circuit comprises a charge amplifier, the charge amplifier amplifies the charge of the discharge loop, and the controller is connected with the charge amplifier and samples the amplified electric signal.

One of the beneficial effects of the embodiment of the application is that: the first detection circuit and the second detection circuit respectively detect the charging signal and the discharging signal of the detected capacitor in the charging process and the discharging process, so that the diversity of sampling data is increased, the accuracy and the stability of the detection result are improved, and the environmental adaptability of the detection system is improved.

Specific embodiments of the present application are disclosed in detail below with reference to the following description and drawings, indicating the manner in which the principles of the present application may be employed. It should be understood that the embodiments of the present application are not limited in scope thereby. The embodiments of the present application include many variations, modifications and equivalents within the spirit and scope of the appended claims.

Features that are described and/or illustrated with respect to one embodiment may be used in the same way or in a similar way in one or more other embodiments in combination with or instead of the features of the other embodiments.

Drawings

Elements and features described in one drawing or one implementation of an embodiment of the present application may be combined with elements and features shown in one or more other drawings or implementations. Furthermore, in the drawings, like reference numerals designate corresponding parts throughout the several views, and may be used to designate corresponding parts as used in more than one embodiment.

The accompanying drawings, which are included to provide a further understanding of the embodiments of the application and are incorporated in and constitute a part of this specification, illustrate embodiments of the application and together with the description serve to explain the principles of the application. It is apparent that the drawings in the following description are only some embodiments of the present application, and that other drawings may be obtained from these drawings without inventive effort for a person of ordinary skill in the art. In the drawings:

FIG. 1 is a schematic diagram of a capacitance detection device according to an embodiment of the present application;

FIG. 2 is another schematic structural diagram of a capacitance detecting device according to an embodiment of the present application;

fig. 3 is a schematic structural diagram of a capacitance detection device according to an embodiment of the present application.

Detailed Description

The foregoing and other features of embodiments of the present application will become apparent from the following description, taken in conjunction with the accompanying drawings. In the following description and drawings, particular implementations of the present application embodiments are disclosed in detail, which demonstrate some of the implementations in which the principles of the present application embodiments may be employed, it being understood that the present application embodiments are not limited to the implementations described, but, on the contrary, the present application embodiments include all modifications, variations, and equivalents falling within the scope of the appended claims.

In the present application embodiments, the term "and/or" includes any and all combinations of one or more of the associated listed terms. The terms "comprises," "comprising," "including," "having," and the like, are intended to reference the presence of stated features, elements, components, or groups of components, but do not preclude the presence or addition of one or more other features, elements, components, or groups of components.

In the embodiments herein, the singular forms "a," an, "and" the "may include plural forms, and should be construed broadly as" one "or" one type "and not as limited to the meaning of" one; furthermore, the term "comprising" is to be interpreted as including both the singular and the plural, unless the context clearly dictates otherwise. Furthermore, the term "according to" should be understood as "at least partially according to … …", and the term "based on" should be understood as "based at least partially on … …", unless the context clearly indicates otherwise.

Various implementations of the examples of the present application are described below with reference to the accompanying drawings. These embodiments are merely illustrative and are not limiting of the examples of the present application.

The embodiment of the application provides a capacitance detection device.

Fig. 1 is a schematic diagram of a capacitance detection device according to an embodiment of the present application.

As shown in fig. 1, the capacitance detection device 100 includes a charging circuit 101, a discharging circuit 102, a first detection circuit 103, and a second detection circuit 104.

As shown in fig. 1, the charging circuit 101 includes a charging power supply 1011, and the charging power supply 1011 is connected to the measured capacitor Cs and charges the measured capacitor Cs; the discharging loop 102 is connected with the measured capacitor Cs and discharges the measured capacitor Cs; the first detection circuit 103 is connected with the charging loop 101 and detects a charging signal; the second detection circuit 104 is connected to the discharge circuit 102 and detects a discharge signal.

As can be seen from the above embodiments, the first detection circuit 103 and the second detection circuit 104 respectively detect the charging signal and the discharging signal of the detected capacitor Cs in the charging process and the discharging process, so as to increase the diversity of the sampled data, improve the accuracy and the stability of the detection result, and improve the environmental adaptability of the detection system.

In one or more embodiments, the capacitance of the measured capacitor is a variable capacitor, for example, the capacitance of the measured capacitor may be different according to the change of the environment, for example, when the measured capacitor is close to the measured object (such as a conductor or an insulator) or the distance from the measured object changes, the capacitance of the measured capacitor may change, and the measured capacitor may be referred to as an external capacitor. However, the present application is not limited thereto, and the measured capacitor may be a capacitor with a constant capacitance. The capacitance to be measured is exemplified as a variable capacitance in the following.

In this embodiment of the present application, the first detection circuit may detect a current signal or a voltage signal, that is, the charging signal may be a current signal or a voltage signal, and stability of the detection system is improved by adding sampling data of a current or a voltage when charging the external capacitor. The present application is not limited in this regard. The following examples are illustrative.

Fig. 2 is another schematic structural diagram of a capacitance detection device according to an embodiment of the present application, showing an exemplary diagram of a first detection circuit detecting a current signal.

As shown in fig. 2, in one or more embodiments, the first detection circuit 103a detects a current signal, the first detection circuit 103a includes a first resistor Rs connected in series with the charging power source 1011 and a current detection circuit detecting a current flowing through the first resistor Rs, and a circuit portion other than the first detection circuit 103a in fig. 2 may be used as the current detection circuit.

Therefore, the current signal is detected in the capacitor charging process, sampling data about the tested capacitor can be increased, the charging state can be judged, and the stability of the detection system is improved.

As shown in fig. 2, in one or more embodiments, the current detection circuit includes a first capacitor C1 connected in parallel with a first resistor Rs and a first amplifier A1 amplifying a voltage signal across the first capacitor C1.

Thus, the high-side circuit detection module composed of the first resistor Rs, the first capacitor C1 and the first amplifier A1 converts the charging current into voltage, and high-precision measurement of the charging current is realized. For high-side circuit detection, see the related art.

Fig. 3 is a schematic diagram of another configuration of the capacitance detecting device according to the embodiment of the present application, showing an exemplary diagram of a circuit configuration in which the first detecting circuit detects a voltage signal.

As shown in fig. 3, in one or more embodiments, the first detection circuit 103b detects a voltage signal, and the first detection circuit 103b is a voltage follower, and detects a charging voltage formed by the capacitor Cs under test during charging.

Therefore, the voltage signal is detected in the capacitor charging process, sampling data about the tested capacitor can be increased, the charging state can be judged, and the stability of the detection system is improved.

In one or more embodiments, as for the voltage follower, for example, as shown in fig. 3, the voltage follower may include an amplifier A2, where one input terminal of the amplifier A2 is connected to one terminal of the capacitor under test, as if the same input terminal is connected to one terminal of the capacitor under test, and the other input terminal of the amplifier A2 is connected to the output terminal of the amplifier, as if the opposite input terminal is connected to the output terminal of the amplifier, and the opposite input terminal is not grounded, that is, the output voltage and the input voltage of the amplifier can be made the same through voltage series negative feedback, so as to achieve the effect of voltage following. Further, regarding the voltage follower, reference is also made to the related art.

In one or more embodiments, as shown in fig. 1 to 3, the capacitance detection device 100 may further include a module for implementing a sampling function, for example, a hold module is adopted in fig. 1 to 3, and in embodiments of the present application, the sample-hold module may perform AD sampling on a current signal or a voltage signal, and for the AD sampling, reference may be made to related art.

In one or more implementations, the sampling function may be implemented with a microcontroller MCU or a microprocessor MPU, that is, the AD sampling may be implemented by a functional circuit on the MCU or the MPU, for example, the AD sampling of the first detection circuit may be implemented with the MCU, and the AD sampling of the second detection circuit may be implemented with the MPU, but the application is not limited thereto, and the MCU and the MPU may be optional as long as the sampling of the current or voltage signal can be implemented.

As shown in fig. 2 and 3, the capacitance detection device 100 may further include a controller 105, and the controller 105 receives the charge signal detected by the first detection circuit 103 (103 a, 103 b) and the discharge signal detected by the second detection circuit 104 and AD samples the charge signal and the discharge signal. Therefore, the charging signal and the discharging signal of the detected capacitor Cs in the charging process and the discharging process are detected, the diversity of sampling data is increased, the accuracy and the stability of a detection result are improved, and the environmental adaptability of the detection system is improved.

In the embodiment of the present application, the controller 105 may be an MCU or an MPU, or may implement sampling of different signals through different controllers, which is not limited in this application.

In one or more embodiments, as shown in fig. 2 and 3, the charging circuit 101 includes a first switch s1, where the first switch s1 switches between a charging state and a non-charging state of the charging circuit 101, for example, when the first switch s1 performs a switching operation to connect the measured capacitor Cs, the charging circuit 101 is in a charging state in which the measured capacitor Cs is charged, and when the first switch s1 performs a switching operation to disconnect the measured capacitor Cs, the charging circuit 101 is in a non-charging state in which the measured capacitor Cs is not charged. Thereby, a controllable charging of the measured capacitance can be achieved.

In one or more embodiments, as shown in fig. 2 and 3, the discharging circuit may include a second switch s2, where the second switch s2 switches the discharging state and the non-discharging state of the discharging circuit 102, for example, when the second switch s2 performs a switching operation to connect the measured capacitor Cs, the discharging circuit 102 is in the discharging state of discharging the measured capacitor Cs, and when the second switch s2 performs a switching operation to disconnect the measured capacitor Cs, the discharging circuit 102 is in the non-discharging state of not discharging the measured capacitor Cs. Thus, controllable discharge of the measured capacitor can be realized.

In one or more embodiments, as shown in fig. 2 and 3, the controller 105 may further include a timing control part performing timing control, the timing control part outputting a timing control signal, and the first switch s1 and the second switch s2 perform a switching operation according to the timing control signal. Thus, reliable control of charge and discharge can be achieved.

In one or more embodiments, the timing control part may issue a timing pulse signal to control the opening and closing of the first switch s1 and the second switch s 2.

For example, when the timing pulse sequence number is 0, the first switch s1 is turned off (the charging circuit 101 is in a charging state), the second switch s2 is turned on (the discharging circuit 102 is in a non-discharging state), the charging circuit charges the capacitor to be measured, when a predetermined charging time elapses, for example, the capacitor to be measured is in a full-charge state, the timing of the charging time can be performed by using the number of timing pulse signals, and when the next timing pulse signal is received after the charging is completed, the first switch s1 is turned on (the charging circuit 101 is in a non-charging state), and the second switch s2 is turned off (the discharging circuit 102 is in a discharging state). Thereby, control of the charging electricity is achieved by the time-series pulse signal.

In this embodiment of the present application, when the first switch s1 is closed and the second switch s2 is opened, the measured capacitor Cs is charged, in the embodiment illustrated in fig. 2, a voltage is formed on the first resistor Rs, in this case, the charging current is converted into a voltage by the high-side current detection circuit, and is received after being sampled by, for example, the MCU AD, and in the embodiment illustrated in fig. 3, the charging voltage formed on the measured capacitor Cs is directly introduced into, for example, the MPU through the follower to perform AD sampling. Thereby, detection and sampling of current or voltage signals during charging is achieved.

In one or more embodiments, the second detection circuit may include a charge amplifier that amplifies the charge of the discharge loop, and the controller is coupled to the charge amplifier and samples the amplified electrical signal.

For example, as shown in fig. 2 and 3, when the first switch s1 is opened and the second switch s2 is closed, the measured capacitor Cs is discharged through the parallel resistor Rp, and in the implementation of the embodiment of fig. 2 and 3, the measured capacitor Cs may be amplified by, for example, a charge amplifier and then sent to, for example, an MCU for AD sampling, and for example, the transimpedance amplifying module 106 shown in fig. 2 and 3 may be used to implement the function of the charge amplifier, and reference may be made to the related technologies of transimpedance amplifying and charge amplifier. In such a detection circuit, the larger the measured capacitance Cs, the longer the discharge time on Rp, the more the charge, the larger the amplifier output, and the magnitude of the sampling value indirectly reflects the magnitude of the measured capacitance Cs. In the embodiment of the application, the second detection circuit can detect the voltage signal, for example, weak charges in the circuit can be converted into an amplified voltage signal proportional to the weak charges through the charge amplifier, so that reliable detection is realized.

Through the above embodiment, the first detection circuit 103 and the second detection circuit 104 detect the charging signal and the discharging signal of the detected capacitor Cs in the charging process and the discharging process, respectively, so as to increase the diversity of sampling data, improve the accuracy and the stability of the detection result, and improve the environmental adaptability of the detection system.

It should be noted that fig. 1 to 3 above only schematically illustrate the capacitance detection device according to the embodiment of the present application, but the present application is not limited thereto, and reference may be made to the related art for the specific details of each structure or component; it is also possible to add structures or components not shown in fig. 1 to 3 or to reduce one or more structures or components in fig. 1 to 3. Reference may be made to the related art for parts or elements not specifically indicated in fig. 1 to 3, which are not limited in this application. For example, as shown in fig. 2 and 3, the capacitance detection circuit may further include a shielding electrode grounded to shield external interference.

While the embodiments of the present application have been described in connection with specific embodiments, it should be apparent to those skilled in the art that these descriptions are intended to be illustrative, and not limiting in scope. Various modifications and alterations to the embodiments of this application may be made by those skilled in the art in light of the spirit and principles of the embodiments of this application, which are also within the scope of the embodiments of this application.

Preferred implementations of the embodiments of the present application are described above with reference to the accompanying drawings. The many features and advantages of the embodiments are apparent from the detailed specification, and thus, it is intended by the appended claims to cover all such features and advantages of the embodiments which fall within the true spirit and scope thereof. Further, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the implementations of the embodiments of the present application to the exact construction and operation illustrated and described, and accordingly, all suitable modifications and equivalents may be resorted to, falling within the scope thereof.

Claims (10)

1. A capacitance detection device, characterized in that the capacitance detection device comprises:

the charging circuit comprises a charging power supply, and the charging power supply is connected with the tested capacitor and charges the tested capacitor;

a discharge loop which is connected with the tested capacitor and discharges the tested capacitor;

a first detection circuit connected to the charging circuit and detecting a charging signal;

and the second detection circuit is connected with the discharge loop and detects a discharge signal.

2. The capacitive sensing apparatus of claim 1, wherein,

the first detection circuit detects a current signal.

3. The capacitive sensing apparatus of claim 2, wherein,

the first detection circuit includes a first resistor connected in series with a charging power supply and a current detection circuit that detects a current flowing through the first resistor.

4. The capacitive sensing apparatus of claim 3, wherein,

the current detection circuit comprises a first capacitor connected in parallel with the first resistor and a first amplifier for amplifying voltage signals at two ends of the first capacitor.

5. The capacitive sensing apparatus of claim 1, wherein,

the first detection circuit detects a voltage signal.

6. The capacitive sensing apparatus of claim 5, wherein,

the first detection circuit is a voltage follower and detects a charging voltage formed by the tested capacitor in a charging process.

7. The capacitance sensing device according to any one of claims 1 to 6,

the measured capacitance is a variable capacitance.

8. The capacitive sensing apparatus of claim 7, wherein,

the capacitance detection device further includes a controller that receives the charge signal detected by the first detection circuit and the discharge signal detected by the second detection circuit, and performs AD sampling on the charge signal and the discharge signal.

9. The capacitive sensing apparatus of claim 8, wherein,

the charging circuit includes a first switch that switches charging and non-charging states of the charging circuit;

the discharge loop comprises a second switch which switches the discharge and non-discharge states of the discharge loop;

the controller includes a timing control unit that outputs a timing control signal, and the first switch and the second switch perform a switching operation according to the timing control signal.

10. The capacitive sensing apparatus of claim 8, wherein,

the second detection circuit comprises a charge amplifier, the charge amplifier amplifies the charge of the discharge loop, and the controller is connected with the charge amplifier and samples the amplified electric signal.